3G/4G Auction: 850MHz Spectrum Might Carry Co-Channel Interference

Government may not be able to offer clean (clear from interference) spectrum in the 850 MHz range that it is planning to auction next month in the upcoming Next Generation Mobile Services auction.

Cellular operators will have to face interference issues in the 850 MHz range as some degree of co-channel interference along borders with neighboring countries will persist, documents available with ProPakistani revealed.

Pakistan Telecommunication Authority (PTA) on May 23 arranged an information session for prospective bidders to explain the auction process, rules and other details. The meeting was attended by Mobilink, Telenor, World Call and Multi Net.

The Auction committee of PTA after preparing the responses to proposals/demands of telecom operators on Information Memorandum (IM) and license template and shared with all stakeholders.

Telecom stakeholders had raised questions with respect to 850 MHz / 900 MHz coexistence and stated that Pakistan has had a mixed band plan for a long time. They said that co-existence between 850 MHz and 900 MHz networks typically requires transmit filters on the 850 MHz base stations and receive filters on at least some 900 MHz base stations.

They further stated that 900 MHz operators may have benefited from the absence of a 850 MHz operator and omitted external receive filters on their base stations. However, with the auction of 850MHz band, the situation will change as operators may need to install receive filters (for their 900MHz bands) in order to coexist with the 850 MHz network in future.

In cases where interference is discovered, Frequency Allocation Board will ensure that the situation is addressed and that the sources of interference are removed.

In the unlikely case that FAB is unable to remove interference from a significant part of city or a region, the 850 MHz operator can expect that the same principles will apply to it as we saw in the past when Zong had faced issues for the spectrum it had bought.

In such cases, 850 MHz operator may be offered compensatory spectrum in the city or region where significant and persistent interference cannot be removed.

“The 850 MHz must, however, expect some degree of co-channel interference along borders with neighboring countries”, confirmed the Auction Committee.

It won’t be out of place to mention that PTA is planning to auction a block in 850MHz spectrum at a base price of $395 million.